StringIO#set_encoding should set the encoding to default external when passed nil
StringIO#puts should print newline when passed nil 1 or more times
Untag passing float rubyspecs
Merge pull request #679 from atambo/stringio_set_encoding_nil

StringIO#set_encoding should set the encoding to default external when passed nil
Merge pull request #680 from atambo/stringio_puts_nil

StringIO#puts should print newline when passed nil 1 or more times
Merge pull request #681 from atambo/untag_float_specs

Untag passing float rubyspecs
Fix some of String#encode! and String#encode rubyspecs.
Include XMLConverter.
Return self if no options and default_internal is nil.
Remove passing specs from tag file.
Verifying if character is corrupted, meaning that one more char is needed.
Merge pull request #682 from josedonizetti/fixing_corrupt_char_problem

Verifying if character is corrupted, meaning that one more char is needed.
Fix travis failures in fileutils due to smarter tmpdir.

Travis started failing after we updated tmpdir to allow using a
world-writable dir if sticky bit is set. The bug that was exposed
lies in FileUtils.remove_entry_secure, where it attempts to open
the "." entry in the target directory primarily to stat, chmod,
and chown it. Because JVM cannot open a stream to a directory
entry, JRuby can't do it either, and because we started allowing
tmpdir to use sticky-bit world-writable dirs, this logic started
getting hit for Dir.mktmpdir's cleanup.

The fix was to directly stat, chown, and chmod the "." entry
rather than opening it as a file, since these operations end up
equivalent.

Note of clarification: this issue has always existed, but most
uses of remove_entry_secure were either already in secure dirs
(non-world-writable) or insecure dirs with no sticky bit (in
which case remove_entry_secure raises an error, correctly). It
only became apparent because of the recent tmpdir change.
Fix 2.0 fileutils.rb as in 610be9f98.
Merge pull request #684 from tychobrailleur/string_encode

Fix some failing rubyspecs for String#encode